Method of storage and heat retaining for treated nodular cast iron

ABSTRACT

NODULAR CAST IRON TREATED WITH AN ALLOYING MEDIUM CONTAINING MAGNESIUM IS POURED INTO AN INLET OF A DOUBLECROSSED INDUCTION FURNACE, THE INLET AND OUTLET CHANNELS OF WHICH ARE SEALED BY THE MELT, FORMING A CLOSED SPACE ABOVE THE MELT FROM WHICH AIR IS EVACUATED AND INTO WHICH PROTECTIVE GAS IS INTRODUCED AT A PRESSURE ABOVE ATMOSPHERIC. THE NOCULAR CAST IRON IS STORED AND KEPT HOT IN THE FURNACE AND IS TAPPED OFF THROUGH THE OUTLET. THE OVERPRESSURE ABOVE THE MELT IS PREFERABLY MAINTAINED AT 0.005   TO 0.3 ATOMSPHERE. CALCIUM CARBIDE MAY BE ADDED FROM TIME TO TIME TO FORM SLAG.



